The present invention relates to a wiper apparatus, and particularly to an apparatus for wiping liquid coating material on a moving strip, such as, for example, a moving strip of metal.
It is heretofore known to apply a coating of liquid material on a surface of a moving strip of metal with liquid coating material applicators. The coating may be used to protect or color the metal, for example. It typically is desirable that the liquid coating material be evenly or uniformly distributed over the surface of the moving strip.
The present invention provides a wiper apparatus for spreading, smoothing or otherwise wiping liquid coating material on a surface of a moving strip, such as, for example, a moving strip of metal. The wiper apparatus comprises first and second wipers, each wiper for alternately wiping the liquid coating material on the surface of the moving strip; and a wiper support coupled to the first and second wipers for moving the first and second wipers between a first orientation wherein the first wiper is adjacent the surface of the moving strip for wiping the liquid coating material on the surface of the moving strip and the second wiper is spaced from the surface of the moving strip, and a second orientation wherein the second wiper is adjacent the surface of the moving strip for wiping the liquid coating material on the surface of the moving strip and the first wiper is spaced from the surface of the moving strip. The first and second wipers desirably comprise felt.
Desirably, the wiper support includes a shaft coupled to at least one of the first and second wipers. The shaft is rotatable to move the first and second wipers between the first and second orientations. The wiper support may further include first and second wiper holders, at least one of which is secured to the shaft. The first wiper holder is secured to the first wiper and the second wiper holder is secured to the second wiper. One or both of the first and second wiper holders define a passageway receiving the shaft.
The shaft may be coupled to the at least one of the first and second wipers in any suitable manner that results in movement of the first and second wipers between the first and second orientations. In a preferred embodiment, for example, there are two shafts, each shaft secured to one or both of the first wiper holder and the second wiper holder. By way of further example, a single shaft can instead be used that is secured to one or both of the first and second wiper holders in accordance with alternative embodiments.
The wiper apparatus may also include a lift assembly for lifting or otherwise moving the first and second wipers between an engaged position in which one of the first and second wipers is adjacent the surface of the moving strip and a disengaged position in which both of the first and second wipers are spaced from the surface of the moving strip. The lift assembly desirably comprises at least one arm coupled to the one or more shafts to move the first and second wipers between the engaged and disengaged positions. The wiper support may include a bearing engaging the arm and the shaft to permit rotation of the shaft relative to the arm to permit movement of the first and second wipers between the first and second orientations. Desirably, there are two arms for moving the first and second wipers between the engaged and disengaged positions, and each arm is secured to one of the shafts. The arms preferably are disposed about the first and second wipers.
In a preferred embodiment, the wiper apparatus further includes a releasable lock for releasably locking each shaft to a respective arm to prevent rotation of the shaft relative to the arm. The releasable lock may, for example, comprise a fastener or other suitable structure coupled to the bearing and movable between a locked position in which the fastener locks the shaft to prevent the shaft from rotating relative to the arm and an unlocked position in which the fastener unlocks the shaft to allow rotation of the shaft relative to the arm.